miR-526b-3p serves as a prognostic factor and regulates the proliferation, invasion, and migration of glioma through targeting WEE1

Decoding the Role of Kinesin Superfamily Proteins in Glioma Progression

Glioma is a highly aggressive and invasive brain tumor with limited treatment options, highlighting the need for novel therapeutic approaches. Kinesin superfamily proteins (KIFs) are a diverse group of motor proteins that play essential roles in cellular processes such as mitosis, intracellular transport, and signal transduction, all of which are crucial for tumorigenesis. This review focuses on the multifaceted role of KIFs in glioma, examining their clinical relevance, contribution to tumor progression, and potential as therapeutic targets. We discuss how KIFs influence key aspects of glioma biology, including cell proliferation, invasion, migration, and metastasis. Furthermore, we explore the regulation of the cell cycle and critical signaling pathways associated with glioma, such as PI3K-Akt, Wnt/β-catenin, and Hedgehog signaling by KIFs. The review also addresses the emerging interplay between KIFs and non-coding RNAs, including circular RNAs (circRNAs) and microRNAs (miRNAs), in glioma progression. Finally, we examine current therapeutic strategies targeting KIFs, including immunotherapy, chemotherapy, and small-molecule inhibitors, and their potential to improve treatment outcomes for glioma patients. By synthesizing these insights, this review underscores the significance of KIFs in glioma pathogenesis and their promise as novel therapeutic targets in the fight against glioma.

The miRNA and PD-1/PD-L1 signaling axis: an arsenal of immunotherapeutic targets against lung cancer

Lung cancer is a severe challenge to the health care system with intrinsic resistance to first and second-line chemo/radiotherapies. In view of the sterile environment of lung cancer, several immunotherapeutic drugs including nivolumab, pembrolizumab, atezolizumab, and durvalumab are currently being used in clinics globally with the intention of releasing exhausted T-cells back against refractory tumor cells. Immunotherapies have a limited response rate and may cause immune-related adverse events (irAEs) in some patients. Hence, a deeper understanding of regulating immune checkpoint interactions could significantly enhance lung cancer treatments. In this review, we explore the role of miRNAs in modulating immunogenic responses against tumors. We discuss various aspects of how manipulating these checkpoints can bias the immune system's response against lung cancer. Specifically, we examine how altering the miRNA profile can impact the activity of various immune checkpoint inhibitors, focusing on the PD-1/PD-L1 pathway within the complex landscape of lung cancer. We believe that a clear understanding of the host's miRNA profile can influence the efficacy of checkpoint inhibitors and significantly contribute to existing immunotherapies for lung cancer patients. Additionally, we discuss ongoing clinical trials involving immunotherapeutic drugs, both as standalone treatments and in combination with other therapies, intending to advance the development of immunotherapy for lung cancer.

LINC01343 targets miR-526b-5p to facilitate the development of hepatocellular carcinoma by upregulating ROBO1

Long noncoding RNAs (lncRNAs) contribute to hepatocellular carcinoma (HCC) progression and development. However, the function and molecular mechanisms of action of LINC01343 in HCC remain unclear. qRT-PCR and western blotting were performed to assess miR-526b-5p, LINC01343, and ROBO1 levels in HCC cell lines and tissue samples. Flow cytometry, transwell, and cell counting kit-8 assays were conducted in vitro to assess how LINC01343 influences the apoptosis, migration, and proliferation of HCC cells. In addition, the role of LINC01343 in the growth of tumors was verified using an in vivo xenograft tumor assay. Specific binding of miR-526b-5p to LINC01343/ROBO1 was validated using RNA immunoprecipitation and dual-luciferase reporter experiments. LINC01343 was upregulated in HCC cells and tissues. In vitro, LINC01343-knockdown Hep3B and Huh-7 cells exhibited enhanced apoptosis and suppressed proliferation and migration. An in vivo study further validated that LINC01343-knockdown repressed tumor growth. In terms of mechanisms, LINC01343 directly sponged miR-526b-5p, negatively modulating its expression. Moreover, further experiments revealed that inhibiting miR-526b-5p could counteract the tumor-suppressive effects of LINC01343-knockdown in Hep3B and Huh-7 cells. ROBO1 was identified as a direct target of miR-526b-5p. ROBO1 knockdown weakens the migratory and proliferative abilities of Hep3B and Huh-7 cells. Nonetheless, the inhibition of miR-526b-5p mitigated this effect. These findings revealed that LINC01343 serves as a vital oncogene in HCC. Moreover, the LINC01343/miR-526b-5p/ROBO1 axis may be a prospective target for HCC treatment.

Synthetic and Medicinal Chemistry Approaches Toward WEE1 Kinase Inhibitors and Its Degraders

WEE1 is a checkpoint kinase critical for mitotic events, especially in cell maturation and DNA repair. Most cancer cells' progression and survival are linked with elevated levels of WEE1 kinase. Thus, WEE1 kinase has become a new promising druggable target. A few classes of WEE1 inhibitors are designed by rationale or structure-based techniques and optimization approaches to identify selective acting anticancer agents. The discovery of the WEE1 inhibitor AZD1775 further emphasized WEE1 as a promising anticancer target. Therefore, the current review provides a comprehensive data on medicinal chemistry, synthetic approaches, optimization methods, and the interaction profile of WEE1 kinase inhibitors. In addition, WEE1 PROTAC degraders and their synthetic procedures, including a list of noncoding RNAs necessary for regulation of WEE1, are also highlighted. From the standpoint of medicinal chemistry, the contents of this compilation serve as an exemplar for the further design, synthesis, and optimization of promising WEE1-targeted anticancer agents.

Serum-derived extracellular vesicles facilitate temozolomide resistance in glioblastoma through a HOTAIR-dependent mechanism

Extracellular vesicle (EV)-mediated transfer of long non-coding RNAs (lncRNAs) has been reported to regulate chemoresistance in various cancers. We herein investigate the therapeutic potential of bioinformatically identified HOTAIR transferred by serum-derived EVs (serum-EVs) in temozolomide (TMZ) resistance of glioblastoma (GBM) and the downstream mechanisms. EVs were isolated from the serum of GBM patients. Expression of HOTAIR was examined in the clinical tissue samples and serum-EVs of GBM patients. The downstream miRNAs of HOTAIR and its target genes were predicted in silico. The effects of the HOTAIR transmitted by serum-EVs in malignant phenotypes, tumor growth, and TMZ resistance were assessed in vitro and in vivo. HOTAIR expression was upregulated in clinical tissues, cells, and serum-EVs of GBM. Co-culture data showed that GBM-serum-EVs facilitated GBM cell proliferative and invasive phenotypes and TMZ resistance by elevating HOTAIR. In GBM cells, HOTAIR competitively bound to miR-526b-3p and weakened miR-526b-3p’s binding ability to EVA1, thus increasing the expression of EVA1. Furthermore, HOTAIR carried by serum-EVs promoted tumor growth and TMZ resistance in vivo by suppressing miR-526b-3p-mediated EVA1 inhibition. GBM-serum-EV-enclosed HOTAIR may augment GBM progression and chemoresistance through miR-526b-3p downregulation and EVA1 upregulation. These results provide a strategy to reduce TMZ resistance in GBM treatment.

MiR-526b-3p Inhibits the Resistance of Glioma Cells to Adriamycin by Targeting MAPRE1

Background

Cell resistance is the main reason for the high mortality in glioma. Adriamycin (ADR) is a treatment drug for glioma and often leads to chemoresistance. Previous studies have confirmed that the abnormal expression of microRNA (miRNA) affects the resistance of glioma cells.

Methods

RT-qPCR and western blot were conducted for detecting miR-526b-3p levels and related protein expressions. CCK8 assay, colony formation, flow cytometry, and Transwell were adopted to assess cell viability, proliferation, apoptosis, and metastasis. Moreover, downstream targets of miR-526b-3p were identified through a dual-luciferase reporter and RNA pull-down analysis.

Results

Nevertheless, miR-526b-3p functions on glioma cell resistance to ADR are not well characterized. This study demonstrated that miR-526b-3p levels were decreased within glioma cells and further decreased within ADR-resistant glioma cells. Then, miR-526b-3p overexpression repressed glioma cell proliferation and invasion while inducing cell apoptosis. Overexpression of miR-526b-3p within ADR-resistant glioma cells obtained similar results, which suggested miR-526b-3p suppressed glioma cell resistance to ADR. Mechanistically, miR-526b-3p targeted MAPKE1 and negatively regulated MAPKE1 expressions. Restoration of MAPKE1 levels reversed miR-526b-3p effects on the glioma process and resistance to ADR.

Conclusion

These results suggest that miR-526b-3p acts as a diagnostic marker in glioma development and therapeutic target of the glioma resistance to ADR.

MicroRNA Alterations Induced in Human Skin by Diesel Fumes, Ozone, and UV Radiation

Epigenetic alterations are a driving force of the carcinogenesis process. MicroRNAs play a role in silencing mutated oncogenes, thus defending the cell against the adverse consequences of genotoxic damages induced by environmental pollutants. These processes have been well investigated in lungs; however, although skin is directly exposed to a great variety of environmental pollutants, more research is needed to better understand the effect on cutaneous tissue. Therefore, we investigated microRNA alteration in human skin biopsies exposed to diesel fumes, ozone, and UV light for over 24 h of exposure. UV and ozone-induced microRNA alteration right after exposure, while the peak of their deregulations induced by diesel fumes was reached only at the end of the 24 h. Diesel fumes mainly altered microRNAs involved in the carcinogenesis process, ozone in apoptosis, and UV in DNA repair. Accordingly, each tested pollutant induced a specific pattern of microRNA alteration in skin related to the intrinsic mechanisms activated by the specific pollutant. These alterations, over a short time basis, reflect adaptive events aimed at defending the tissue against damages. Conversely, whenever environmental exposure lasts for a long time, the irreversible alteration of the microRNA machinery results in epigenetic damage contributing to the pathogenesis of inflammation, dysplasia, and cancer induced by environmental pollutants.

The LMCD1-AS1/miR-526b-3p/OSBPL5 axis promotes cell proliferation, migration and invasion in non-small cell lung cancer

PURPOSE

To explore the specific role and regulatory mechanism of oxysterol binding protein like 5 (OSBPL5) in non-small cell lung cancer (NSCLC).

METHODS AND RESULTS

Quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrated that OSBPL5 expression was notably elevated in NSCLC tissues and cell lines, and Kaplan-Meier analysis manifested that high OSBPL5 expression was closely related to the poor prognosis of NSCLC patients. Besides, according to the results from western blot analysis, cell counting kit-8, EdU and Transwell assays, knockdown of OSBPL5 suppressed NSCLC cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) process. Additionally, by performing qRT-PCR analysis, luciferase reporter and RNA pull-down assays, we verified that OSBPL5 was a downstream target of miR-526b-3p and long noncoding RNA (lncRNA) LMCD1-AS1 served as a sponge for miR-526b-3p. Moreover, from rescue assays, we observed that OSBPL5 overexpression offset LMCD1-AS1 knockdown-mediated inhibition in cell proliferation, migration, invasion and EMT in NSCLC.

CONCLUSIONS

This paper was the first to probe the molecular regulatory mechanism of OSBPL5 involving the LMCD1-AS1/miR-526b-3p axis in NSCLC and our results revealed that the LMCD1-AS1/miR-526b-3p/OSBPL5 axis facilitates NSCLC cell proliferation, migration, invasion and EMT, which may offer a novel therapeutic direction for NSCLC.

MiR-526b-3p Attenuates Breast Cancer Stem Cell Properties and Chemoresistance by Targeting HIF-2α/Notch Signaling

Chemoresistance is a severe clinical challenge in breast cancer. Hypoxia and cancer stem cells (CSCs) contribute to the paclitaxel (PTX) resistance, but the molecular mechanisms are still elusive. MicorRNAs (miRNA) have been considered a promising therapeutic strategy in various cancers. Here, we identified the crucial function of miR-526b-3p in regulating PTX resistance and CSC properties. Our data demonstrated that miR-526b-3p mimic repressed the cell viability of breast cancer cells. The counts of Edu-positive cells were reduced by miR-526b-3p in breast cancer cells. Meanwhile, the apoptosis of breast cancer cells was induced by miR-526b-3p. Tumorigenicity analysis in the nude mice confirmed that miR-526b-3p attenuated the breast cancer cell growth in vivo. Significantly, hypoxia could enhance IC50 value of PTX in breast cancer cells. IC50 value of PTX was induced in breast cancer mammospheres. The hypoxia-inducible factor 2α (HIF-2α) expression was enhanced, but miR-526b-3p expression was repressed under hypoxia in breast cancer cells. Also, breast cancer mammospheres presented high HIF-2α expression and low miR-526b-3p expression. The inhibition of miR-526b-3p enhanced the IC50 value of PTX in breast cancer cells. MiR-526b-3p inhibitor enhanced the colony formation counts of PTX-treated breast cancer cells. The treatment of miR-526b-3p mimic suppressed the sphere formation counts of breast cancer cells and inhibited ALDH1 and Nanog expression. MiR-526b-3p was able to target HIF-2α in the cells. The overexpression enhanced but miR-526b-3p reduced the IC50 value of PTX in breast cancer cells, in which the overexpression of HIF-2α could rescue the miR-526b-3p-inhibited IC50 value of PTX. Overexpression of HIF-2α reversed miR-526b-3p-regulated apoptosis, colony formation ability, and ALDH1 and Nanog expression in the cells. Interestingly, the overexpression of HIF-2α induced but miR-526b-3p repressed the expression of HIF-2α, Hey2, and Notch in PTX-treated breast cancer cells, while HIF-2α could reverse the effect of miR-526b-3p. In conclusion, miR-526b-3p attenuated breast cancer stem cell properties and chemoresistance by targeting HIF-2α/Notch signaling. MiR-526b-3p may be utilized in the relieving chemoresistance in breast cancer.

Total pancreatectomy with intraportal islet autotransplantation for pancreatic malignancies: a literature overview

INTRODUCTION

'Brittle Diabetes' (BD) is a life-threatening metabolic complication after total pancreatectomy (TP). More than 500 Intraportal islet autotransplantation (IAT) have been performed to prevent this complication, with almost 70% insulin independence after 3 years. Even when insulin independence was not achieved, IAT successfully prevented severe hypoglycemia. Currently, preliminary results for oncologic situations are promising, but their oncological outcomes are still a matter of debate.

AREAS COVERED

We performed a bibliographic research of the last 25 years of data. Articles published in English in peer-reviewed journals were retained. In France, auto- and allo-islet transplantation was recently recognized as a valuable treatment for BD by the national health authority. While accepted for benign diseases, the risk of tumor spreading after IAT in oncologic situations is a source of concern.

EXPERT OPINION

Preliminary results of IAT in oncological situations are very encouraging. So far, there is no evidence of tumor dissemination. In our opinion, to overcome BD TP with IAT for resectable pancreatic malignancies in patients with a higher risk of postoperative pancreatic fistula and extended pancreatic cancers can be safely performed. Diagnosis of malignancy should not be considered as an exclusion criterion for IAT.

miR-526b-3p inhibits lung cancer cisplatin-resistance and metastasis by inhibiting STAT3-promoted PD-L1

Chemotherapy remains the primary treatment of advanced solid cancer, including lung cancer. However, as first-line treatment, cisplatin-based therapy is restricted by the frequent development of drug resistance. Increasing data showed that the programmed cell death protein ligand 1 (PD-L1) plays a vital role in regulating cisplatin resistance. However, the underlying mechanisms are not fully understood. We found that miR-526b-3p expression declined while PD-L1 was elevated in cisplatin-resistant lung cancer compared to that in cisplatin-sensitive lung cancer by analyzing clinical samples. Significantly, miR-526b-3p was associated with response to cisplatin negatively. We further demonstrated that miR-526b-3p reversed cisplatin resistance, suppressed metastasis, and activated CD8+ T cells in a STAT3/PD-L1-dependent manner. Thus, our findings extended the knowledge of PD-L1-mediated cisplatin resistance of lung cancer. In addition, the introduction of miR-526b-3p provided a new clue to improve the anti-tumor effects of the combination of immunotherapy and chemotherapy.

Long non-coding RNA HOTAIR promotes hepatocellular carcinoma progression by regulating miR-526b-3p/DHX33 axis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common human cancers. Long non-coding RNAs (lncRNAs) play pivotal roles in progression of various cancers, including HCC.

OBJECTIVE

We aimed to explore the exact role and underlying mechanism of lncRNA HOX transcript antisense intergenic RNA (HOTAIR) in HCC.

METHODS

Quantitative real time polymerase chain reaction (qRT-PCR) was carried out to determine the levels of HOTAIR, DEAH-box helicase 33 (DHX33) and miR-526b-3p. Western blot assay was used to detect the protein level of DHX33. Besides, cell proliferation and apoptosis were assessed by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and flow cytometry analysis, respectively. Cell migration and invasion were detected by transwell assay. The interaction between miR-526b-3p and HOTAIR or DHX33 was predicted by starbase and confirmed by the dual-luciferase reporter assay. Murine xenograft model was established through injecting Huh7 cells transfected with sh-NC or sh-HOTAIR.

RESULTS

The levels of HOTAIR and DHX33 were increased in HCC tissues and cells. Knockdown of either HOTAIR or DHX33 suppressed proliferation, migration and invasion but increased apoptosis in HCC cells. Moreover, DHX33 overexpression reversed the suppressive effect of HOTAIR knockdown on progression of HCC cells. Interestingly, miR-526b-3p could directly bind to HOTAIR, and DHX33 was a direct target of miR-526b-3p. Additionally, interference of HOTAIR restrained the tumor growth by upregulating miR-526b-3p and downregulating DHX33 in vivo.

CONCLUSIONS

HOTAIR knockdown suppressed cell proliferation, migration and invasion, and promoted apoptosis via regulating miR-526b-3p/DHX33 axis in HCC cells, providing a potential avenue for treatment of HCC.

Downregulation of Circ_0071589 Suppresses Cisplatin Resistance in Colorectal Cancer by Regulating the MiR-526b-3p/KLF12 Axis

BACKGROUND

Chemoresistance is one key factor for the failure of cisplatin (CDDP)-based therapy in colorectal cancer (CRC). Although circular RNAs (circRNAs) are associated with chemoresistance development, the role and mechanism of hsa_circ_0071589 (circ_0071589) in the development of CDDP resistance in CRC remain unclear.

METHODS

CDDP-resistant and sensitive CRC samples were collected. CDDP-resistant HCT116/CDDP and LOVO/CDDP cells were established. The levels of circ_0071589, microRNA (miR)-526b-3p and Krüppel-like factor 12 (KLF12) were detected via quantitative reverse transcription polymerase chain reaction, Western blot or immunohistochemistry. Cell viability, proliferation, cycle process, apoptosis, migration and invasion were examined via Cell Counting Kit-8, flow cytometry, transwell assay and Western blot. The association between miR-526b-3p and circ_0071589 or KLF12 was predicted by starBase, and explored via dual-luciferase reporter assay and RNA immunoprecipitation. The effect of circ_0071589 on CDDP resistance in CRC in vivo was investigated using a xenograft model.

RESULTS

Circ_0071589 level was upregulated in CDDP-resistant CRC tissue samples and cell lines. Circ_0071589 knockdown inhibited CDDP resistance, proliferation, migration and invasion, and promoted apoptosis in CDDP-resistant CRC cells. Circ_0071589 was a sponge for miR-526b-3p. MiR-526b-3p knockdown reversed the role of circ_0071589 inhibition in CDDP resistance. MiR-526b-3p suppressed CDDP resistance by directly targeting KLF12. Circ_0071589 regulated KLF12 expression through modulating miR-526b-3p. Circ_0071589 knockdown aggravated CDDP-induced reduction of xenograft tumor growth by upregulating miR-526b-3p and decreasing KLF12.

CONCLUSION

Knockdown of circ_0071589 repressed CDDP resistance in CDDP-resistant CRC cells by regulating the miR-526b-3p/KLF12 axis.

Long non-coding RNA LINC00470 in serum derived exosome: a critical regulator for proliferation and autophagy in glioma cells

Background

To explore the mechanism of LINC00470 in serum exosomes from glioma patients regulating the autophagy and proliferation of glioma cells.

Methods

Exosomes were extracted from glioma patients (GBM-exo). Expression of LINC00470 in exosomes was analyzed with the clinicopathological characteristics of glioma patients. Glioma mouse model was established. The effects of LINC00470, miR-580-3p and WEE1 on cell autophagy and proliferation, as well as the activation of PI3K/AKT/mTOR pathway were measured. Dual luciferase reporter assay and RNA immunoprecipitation (RIP) were conducted to validate the binding of LINC00470 and miR-580-3p and of miR-580-3p and WEE1.

Results

LINC00470 overexpressed in GBM-exo and associated with disease severity and postoperative survival time of glioma patients. GBM-exo deteriorated tumor progression in nude mice. Cells incubated with GBM-exo or transfected with pcDNA3.1-LINC00470/miR-580-3p inhibitor/pcDNA3.1-WEE1 had less autophagosome, downregulated LC3-II/LC3-I and Beclin1 expression levels and increased expression of p62 as well as strengthened proliferation ability. The PI3K/AKT/mTOR pathway was activated. LINC00470 competitively bound to miR-580-3p with WEE1.

Conclusion

LINC00470 in GBM-exo can bind to miR-580-3p in glioma cells to regulate WEE1 expression and activate the PI3K/AKT/mTOR pathway, thereby inhibiting autophagy and enhancing the proliferation of glioma cells.

Mechanism of Long Non-Coding RNA Homeobox Transcript Antisense RNAs Regulates Rheumatoid Arthritis Synovial Fibroblasts Multiplication, Immigration, and Invasion

Long non-coding RNA HOX transcript antisense RNAs (LncRNA HOTAIR) are aberrantly expressed in rheumatoid arthritis synovial fibroblasts (RASFs), the main cells in rheumatoid arthritis (RA). The inhibition, proliferation, and migrative ability of these cells offer one of the most important therapies for RA. To investigate HOTAIR in RA, 72 patients with RA were selected along with 72 healthy volunteers. Serum HOTAIR and miRNA-526b-3p levels were measured in the study groups by qRT-PCR. Following the primary isolation and culture of RASFs, HOTAIR and miRNA-526b-3p expression was detected in RASFs using qRT-PCR and the CCK-8 method was used to measure the cell proliferative capacity. The TNF-α and IL-1β levels were measured using enzyme-linked immunosorbent assay, while cell motility and invasive capacity were tested by the wound healing assay and transwell chamber assay, respectively. The dual-luciferase reporter assay measured the target-relationship of HOTAIR and miRNA-526b-3p. Western blot detected MMP-2 and MMP-13 protein levels in the samples. We show that serum HOTAIR expression levels were dramatically augmented (P < 0.05) in RA patients compared with the healthy individuals. However, the miRNA-526b-3p level was dramatically reduced (P < 0.05). Transfection of si-HOTAIR significantly reduced the OD value of RASFs, while the TNF-α level, IL-1β level, migration healing rate, MMP-2 protein expression, MMP-13 protein expression (P < 0.05), and the invasive ability were all dramatically debased (P < 0.05). HOTAIR could be a competing endogenous RNAs for miRNA-526b-3p. Inhibiting miR-526b-3p expression could dramatically reduce silent HOTAIR on multiplication, immigration, invasion, and inflammatory factor secretion of RASFs. These findings provide evidence that silent HOTAIR inhibits multiplication, immigration, invasion, and inflammatory factor secretion of RASFs by up-regulating the expression of miRNA-526b-3p.

LncRNA LINC00689 Promotes the Tumorigenesis of Glioma via Mediation of miR-526b-3p/IGF2BP1 Axis

Glioma ranks first among the aggressive brain tumors all over the world. LncRNA LINC00689 has been confirmed to play key roles in the progression of cancers, and LINC00689 was upregulated in glioma. However, the biological function of LINC00689 in glioma is unclear. qRT-PCR was applied to detect the expressions of LINC00689 and miR-526b-3p in glioma cells. Dual-luciferase report was performed to examine the relation among LINC00689, miR-526b-3p, and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1). Then, the growth, migration, and invasion of glioma cells were detected by colony formation, flow cytometry, and transwell assay, respectively. The expressions of p21, cleaved caspase 3, and MAPK signaling-related proteins in glioma cells were tested by western blotting. Finally, xenograft mice model was established to detect the effect of LINC00689 on tumor growth of glioma in vivo. LINC00689 was upregulated in glioma cells, while miR-526b-3p was downregulated. In addition, LINC00689 bound to miR-526b-3p, and IGFBP1 was targeted by miR-526b-3p. Moreover, LINC00689 knockdown or upregulation of miR-526b-3p inhibited the proliferation of glioma cells and induced the apoptosis. Consistently, the migration and invasion of glioma cells were notably reduced by LINC00689 shRNA/miR-526-3p mimics. miR-526b-3p inhibitor or IGF2BP1 upregulation could reverse the effect of LINC00689 knockdown or miR-526b-3p mimics. Finally, knockdown of LINC00689 inhibited the tumor growth of glioma in vivo through regulating miR-526b-3p/IGF2BP1/MAPK axis. In conclusion, silencing of LINC00689 could inhibit the tumorigenesis of glioma via mediation of miR-526b-3p/IGF2BP1 axis. LINC00689 may serve as a new target for the treatment of glioma.

miR-665 is downregulated in glioma and inhibits tumor cell proliferation, migration and invasion by targeting high mobility group box 1

Glioma is the most common brain tumor in adults. microRNAs (miRNAs/miRs) play an essential role in tumor development and progression. The present study aimed to investigate the potential clinical significance and function of miR-665 in glioma. Reverse transcription-quantitative PCR analysis was used to detect the expression of miR-665 in glioma tissues and cells. Survival curves were constructed using the Kaplan-Meier method. Cox regression analysis was performed to investigate the prognostic significance of miR-665. Cell Counting Kit-8 and Transwell assays were used to evaluate the role of miR-665 in glioma. Bioinformatics analysis and Dual-luciferase reporter assays were used to predict the putative direct targets of miR-665. Western blotting was used to evaluate the activity of the Wnt/β-catenin pathway. The relative expression of miR-665 was decreased in glioma tissues and cells and this downregulation was significantly associated with the Karnofsky performance scale score and World Health Organisation grade. Patients with glioma with low miR-665 expression had a shorter overall survival time compared with the high expression group. Besides, overexpression of miR-665 suppressed the proliferation, migration and invasion of glioma cells, while knockdown of miR-665 promoted these cellular behaviors. High mobility group box (HMGB)1 was a direct target of miR-665. It was also demonstrated that miR-665 may suppress glioma progression by targeting HMGB1 and inhibiting the Wnt/β-catenin pathway. Taken together, these data suggested that miR-665 may have a tumor suppressor role in glioma by targeting HMGB1. Therefore, miR-665 may be a novel prognostic biomarker and the miR-665/HMGB1 axis may be a novel therapeutic target for the treatment of glioma.

hsa_circ_0085539 Promotes Osteosarcoma Progression by Regulating miR-526b-5p and SERP1

This study aimed to expand the competing endogenous RNA network in osteosarcoma (OS) involving hsa_circ_0085539 and its downstream target miR-526b-5p. The expression levels of circ_0085539, miR-526b-5p, and stress-associated endoplasmic reticulum protein 1 (SERP1) mRNA in OS tissues and cells were detected and analyzed by qRT-PCR. After that, the interrelationships between these three genetic materials were validated with a luciferase reporter assay system. The effect of the circ_0085539/miR-526b-5p/SERP1 axis on OS cell malignancy phenotypes was further assessed using in vitro assays, including cell counting kit-8 (CCK-8) assays, colony foci formation assays, wound-healing migration assays, and transwell invasion assays. To determine the function of circ_0085539 on OS tumor growth in vivo, a xenograft formation assay was performed. In OS tissues and cells, the expression of circ_0085539 and SERP1 was upregulated, while that of miR-526b-5p was downregulated. After experimental analyses, it was found that silencing circ_0085539 inhibited the aggression of OS in vivo and in vitro. Mechanistic investigations also revealed that circ_0085539 could sponge miR-526b-5p and that miR526b-5p could directly target SERP1. The cytological experiments in vitro demonstrated that miR-526b-5p could restore the effect of circ_0085539 in terms of promoting OS malignancy phenotypes by suppressing SERP1. Overall, the present study validated that hsa_circ_0085539 could promote the progression of OS by regulating miR-526b-5p/SERP1.

Long Noncoding RNA HEIH Promotes Proliferation, Migration and Invasion of Retinoblastoma Cells Through miR-194-5p/WEE1 Axis

Background

Abnormally expressed long noncoding RNA (lncRNA) high expression in hepatocellular carcinoma (HEIH) has been implicated in many types of human cancer, and plays crucial roles in tumor development and progression. However, little is known about its function in retinoblastoma.

Methods

qRT-PCR was used to determine the expression levels of HEIH, miR-194-5p and WEE1 in retinoblastoma tissues and cell lines. The trypan blue exclusion method, colony formation assay, wound-healing assay and transwell invasion assay were performed to evaluate the effects of HEIH, miR-194-5p and WEE1 on cell proliferation, migration and invasion. Bioinformatics analysis, dual-luciferase reporter assay and Western blot were employed to investigate the regulatory relationship among HEIH, miR-194-5p and WEE1.

Results

We found that HEIH was up-regulated in retinoblastoma tissues and cell lines. Furthermore, high level of HEIH was associated with TNM stage, optic nerve invasion and choroidal invasion of patients with retinoblastoma. Functional studies showed that HEIH knockdown significantly suppressed retinoblastoma cell proliferation, migration and invasion. Mechanistically, HEIH promoted retinoblastoma progression by serving as a sponge of miR-194-5p to regulate WEE1 expression.

Conclusion

Our work suggests that HEIH acts as an oncogenic lncRNA to promote retinoblastoma proliferation and metastasis, providing a new insight into the retinoblastoma treatment.

Comprehensive circular RNA expression profiling constructs a ceRNA network and identifies hsa_circ_0000673 as a novel oncogene in distal cholangiocarcinoma

Circular RNAs (circRNAs) play an important role in cholangiocarcinoma (CCA) development; however, the expression and functions of circRNAs in distal CCA (dCCA) remain unknown. Herein, we explored the expression profile of circRNAs in six paired dCCA tumor and adjacent normal tissue samples using microarray. A total of 171 differentially expressed (DE) circRNAs were identified in dCCA tissues. Host genes of DE circRNAs were enriched in the cellular cytoskeleton and adheren junction. Bioinformatics analyses were used to establish a circRNA-microRNA-mRNA network for dCCA. Protein-protein interaction networks were constructed, and five hub genes were associated with the regulation of the cell cycle based on gene set enrichment analyses. Five DE circRNAs were validated with qRT-PCR in 40 pairs of dCCA tissues, and hsa_circ_0000673 showed promising diagnostic performance in distinguishing dCCA from normal tissues (AUC = 0.85, p < 0.01). Overexpression of hsa_circ_0000673 was associated with tumor invasion (p = 0.001), poor differentiation (p = 0.041), and residual tumor (p = 0.044). In vitro experiments indicated that inhibition of hsa_circ_0000673 suppressed the proliferation, migration, and invasion of CCA cells. This research provided a landscape of dysregulated circRNAs in dCCA and identified hsa_circ_0000673 as a potential biomarker and therapeutic target for dCCA.

CircRNA circUGGT2 Contributes to Hepatocellular Carcinoma Development via Regulation of the miR-526b-5p/RAB1A Axis

Background

Hepatocellular carcinoma (HCC) is a common malignant tumor in the world. Circular RNA hsa_circ_0008274 (circUGGT2) is reported to be upregulated in HCC tissues. Notwithstanding, the role and regulatory mechanism of circUGGT2 in HCC are indistinct.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was implemented to examine the levels of circUGGT2, microRNA (miR)-526b-5p, and ras-related protein Rab-1A (RAB1A) mRNA in HCC tissues and cells. Cell proliferation and colony formation were assessed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) or colony formation assays. The levels of cyclin D1, proliferating cell nuclear antigen (PCNA), and RAB1A were detected with Western blotting. Cell cycle progression, migration, and invasion were evaluated by using flow cytometry or transwell assays. The relationship between circUGGT2 or RAB1A and miR-526b-5p was verified via dual-luciferase reporter and/or RNA pull-down assays. Xenograft assay was executed to confirm the role of circUGGT2 in vivo.

Results

We observed that circUGGT2 and RAB1A were upregulated while miR-526b-5p was downregulated in HCC tissues and cells. CircUGGT2 silencing suppressed tumor growth in vivo and curbed proliferation, colony formation, cell cycle progression, migration, and invasion of HCC cells in vitro. Mechanically, circUGGT2 regulated RAB1A expression via competitively binding to miR-526b-5p. Also, the inhibitory influence of circUGGT2 silencing on the malignancy of HCC cells was overturned by miR-526b-5p inhibitor. Furthermore, RAB1A overexpression reversed the suppressive influence of miR-526b-5p mimic on the malignancy of HCC cells.

Conclusion

CircUGGT2 silencing inhibited HCC development via modulating the miR-526b-5p/RAB1A axis, providing a possible target for HCC treatment.

LncRNA LINC00689 Promotes the Progression of Gastric Cancer Through Upregulation of ADAM9 by Sponging miR-526b-3p

Introduction

Increasing studies have demonstrated that noncoding RNAs, including miRNAs and lncRNAs, have vital roles in mediating cancer progression. However, the expression features and biological functions of LINC00689 in gastric cancer (GC) remain largely unknown. This study was designed to investigate the functions of LINC00689, miR-526b-3p and ADAM9 as well as their interactions in GC.

Methods

Real time PCR(RT-PCR) was used to detect the expression of LINC0068, miR-526b-3p and ADAM9 in both GC tissues or cell lines. Gain- and loss- of functions of assays were conducted to verify the role of LINC0068, miR-526b-3p and ADAM9 in GC development. Cell proliferation were determined by CCK8 assay and transwell assay and scratch wound-healing assay were used to test cell invasion and migration. Further, the relationships between LINC00689 and miR-526b-3p, miR-526b-3p and ADAM9 were predicted by bioinformatics analysis and then proved by Luciferase reporter assay and RNA Immunoprecipitation(RIP) assay.

Results

We found that LINC00689 was upregulated in GC tissues and positively correlated with advanced tumor stage and tumor size, while miR-526b-3p was downregulated. Furthermore, gain- and loss-of-function experiments revealed that LINC00689 promoted the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of GC cells, while miR-526b-3p had the opposite effects. The underlying mechanisms indicated that LINC00689 functioned as a competing endogenous RNA (ceRNA) by sponging miR-526b-3p in GC cells. Further investigations confirmed that ADAM9 was a direct target of miR-526b-3p and positively modulated the progression of GC.

Conclusion

Our study suggests that LINC00689 functions as a novel oncogenic lncRNA in the development of GC by promoting ADAM9 expression through suppression of miR-526b-3p.

Clinical significance of miR-33b in glioma and its regulatory role in tumor cell proliferation, invasion and migration

Background: This study aimed to investigate the clinical significance of microRNA-33b (miR-33b) in glioma patients and its biological function in tumor progression. Materials & methods: Expression of miR-33b was measured using quantitative real-time RT-PCR. Diagnostic and prognostic values of miR-33b were assessed by the receiver operating characteristics curve and Kaplan-Meier (KM) survival assay. The functional role of miR-33b was further analyzed. Results: Expression of miR-33b in glioma patients and cells was decreased. Expression of miR-33b had high diagnostic accuracy and could predict a poor prognosis. Overexpression of miR-33b led to suppressed glioma cell proliferation, migration and invasion. Conclusion: Decreased expression of miR-33b serves a promising biomarker in the diagnosis and prognosis of glioma, and may be a potential therapeutic target.

MicroRNA-4317 predicts the prognosis of breast cancer and inhibits tumor cell proliferation, migration, and invasion

Previous researches have indicated that miR-4317 was aberrantly expressed in several tumors. However, the potential role of miR-4317 in breast cancer is still unclear. The aim of this study was to investigate the potential role of miR-4317 in breast cancer. The relative expression levels of miR-4317 were detected in breast cancer tissues and cell lines using qRT-PCR analysis. The Kaplan-Meier survival curve and multivariate Cox regression analyses were used to investigate the prognostic significance of miR-4317 in breast cancer. CCK-8 and Transwell assays were performed to evaluate the effects of miR-4317 on cell proliferation, migration, and invasion. The results showed that miR-4317 expression was decreased in breast cancer tissues and cell lines. Downregulation of miR-4317 was significantly associated with lymph node metastasis, TNM stage, and poor prognosis. Overexpression of miR-4317 inhibited proliferation, migration, and invasion of breast cancer cells, while downregulation of miR-4317 exhibited the opposite effects. MYD88 may be a direct target of miR-4317. The results suggest miR-4317 may play a tumor suppressor role in breast cancer and inhibit proliferation, migration, and invasion of breast cancer cells by targeting MYD88. The findings provide novel evidence of miR-4317 as a potential prognostic biomarker and therapeutic target for breast cancer.

Circular RNA PVT1 promotes metastasis via regulating of miR-526b/FOXC2 signals in OS cells

As a class of covalently closed non-coding RNAs, circular RNAs (circRNAs) are key regulators in various malignancies including osteosarcoma (OS). In the present study, we found that circular RNA PVT1 (circPVT1) was up-regulated in OS and correlated with poor prognosis of patients with OS. Functionally, we showed that knockdown of circPVT1 suppressed OS cells metastasis. In addition, we found that (forkhead box C2) FOXC2 was a downstream gene in circPVT1-mediated metastasis in OS cells. We demonstrated that circPVT1 promoted OS cells metastasis via post-transcriptionally regulating of FOXC2. Furthermore, we revealed that microRNA 526b (miR-526b) was a key bridge which connected circPVT1 and FOXC2. We showed that miR-526b was down-regulated in OS tissue and cell lines. Through a transwell assay, we found that miR-526b suppressed OS cells metastasis by targeting of FOXC2. We also showed that miR-526b targeted circPVT1 via similar mircoRNA response elements (MREs) as it did for FOXC2. Finally, we proved that circPVT1 decoyed miR-526b to promote FOXC2-mediated metastasis in OS cells. In brief, our current study demonstrated that circPVT1, functioning as an oncogene, promotes OS cells metastasis via regulation of FOXC2 by acting as a ceRNA of miR-526b. CircPVT1/miR-526b/FOXC2 axis might be a novel target in molecular treatment of OS.

Quercetin radiosensitizes non-small cell lung cancer cells through the regulation of miR-16-5p/WEE1 axis

BACKGROUND

Quercetin, a widely distributed bioflavonoid, plays a role in combating diverse human cancers including non-small cell lung cancer (NSCLC). However, the role of quercetin in reversing the radioresistance of NSCLC cells and its underlying mechanism are far from being elucidated.

METHOD

Radiation-resistant NSCLC cell lines were established. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-16-5p and WEE1 G2 checkpoint kinase (WEE1) mRNA in radiation-resistant cells. After being treated with different concentrations of quercetin and different doses of X-ray, cell proliferation and apoptosis were monitored by CCK-8 assay, colony formation assay, and flow cytometry, respectively. Ultimately, the targeting relationship between miR-16-5p and WEE1 was verified via a dual fluorescent reporter gene assay.

RESULTS

The expression of miR-16-5p was down-regulated in radiation-resistant cells, while the expression of WEE1 was up-regulated. Quercetin enhanced the radiosensitivity of NSCLC cells in a dose- and time-dependent manner. Furthermore, quercetin treatment increased the expression of miR-16-5p and decreased the expression of WEE1. The function of quercetin was reversed by miR-16-5p inhibitors or the transfection of WEE1 overexpressing plasmids.

CONCLUSION

In conclusion, quercetin enhanced the radiosensitivity of NSCLC cells via modulating the expression of miR-16-5p and WEE1.

Identification and validation of a three-gene signature as a candidate prognostic biomarker for lower grade glioma

Background

Lower grade glioma (LGG) are a heterogeneous tumor that may develop into high-grade malignant glioma seriously shortens patient survival time. The clinical prognostic biomarker of lower-grade glioma is still lacking. The aim of our study is to explore novel biomarkers for LGG that contribute to distinguish potential malignancy in low-grade glioma, to guide clinical adoption of more rational and effective treatments.

Methods

The RNA-seq data for LGG was downloaded from UCSC Xena and the Chinese Glioma Genome Atlas (CGGA). By a robust likelihood-based survival model, least absolute shrinkage and selection operator regression and multivariate Cox regression analysis, we developed a three-gene signature and established a risk score to predict the prognosis of patient with LGG. The three-gene signature was an independent survival predictor compared to other clinical parameters. Based on the signature related risk score system, stratified survival analysis was performed in patients with different age group, gender and pathologic grade. The prognostic signature was validated in the CGGA dataset. Finally, weighted gene co-expression network analysis (WGCNA) was carried out to find the co-expression genes related to the member of the signature and enrichment analysis of the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were conducted for those co-expression network. To prove the efficiency of the model, time-dependent receiver operating characteristic curves of our model and other models are constructed.

Results

In this study, a three-gene signature (WEE1, CRTAC1, SEMA4G) was constructed. Based on the model, the risk score of each patient was calculated with LGG (low-risk vs. high-risk, hazard ratio (HR) = 0.198 (95% CI [0.120-0.325])) and patients in the high-risk group had significantly poorer survival results than those in the low-risk group. Furthermore, the model was validated in the CGGA dataset. Lastly, by WGCNA, we constructed the co-expression network of the three genes and conducted the enrichment of GO and KEGG. Our study identified a three-gene model that showed satisfactory performance in predicting the 1-, 3- and 5-year survival of LGG patients compared to other models and may be a promising independent biomarker of LGG.

YY1 promotes colorectal cancer proliferation through the miR-526b-3p/E2F1 axis

We previously reported that E2F1 expression is up-regulated and positively correlated with the malignant phenotypes of colorectal cancer (CRC). However, the underlying mechanisms leading to the aberrant up-regulation of E2F1 in CRC have not been clarified. In this study, we observed that miR-526b-3p directly targets the 3'UTR of E2f1 mRNA, leading to reduced E2F1 expression. Overexpression of miR-526b-3p inhibited the proliferation of CRC cells by decreasing the level of E2F1. We also found that the Ying Yang 1 (YY1)-dependent transcriptional suppression of miR-526b-3p is responsible for the up-regulation of E2F1 in CRC, in which YY1 binds to the promoter of miR-526b gene and recruits histone deacetylase (HDAC). Knockdown of YY1 led to cell cycle arrest and diminished colony formation in CRC cells partly through relieving the miR-526b-3p suppression. Clinical analysis showed that YY1 and E2F1 were negatively correlated with miR-526b-3p in CRC tissues. Moreover, a high level of YY1 and E2F1, or a low level of miR-526b-3p, predicted poor survival of CRC patients. In conclusion, our findings highlight the dysregulation of the YY1/miR-526b-3p/E2F1 axis in CRC development, implicating a novel regulatory pathway for E2F1 as a potential therapeutic target in CRC.